In the early days of the Internet, most web sites were based on complete hypertext markup language (HTML) pages. Each action that was performed required that a complete page be loaded from the server. This process was inefficient, as all page content disappeared, and was regenerated. Each time the browser reloaded a page because of a partial change, all of the content had to be re-sent, even though only some of the information had changed. This places additional load on the server and uses excessive bandwidth.